Thermostatic alarm.



I. S. SHULTZ.

THERMOSTATIG ALARM.

APPLICATION FILED JAN.18, 1911.

1,055,815, Patented Mar. 11,1913.

F illllll =E-EZW IDA S. SHULTZ, OF EASTON, PENNSYLVANIA.

THERMOSTA'IIC ALARM.

Specification of Letters Patent.

Patented Mar. 11, 1913.

Application filed January 18, 1911. Serial No. 603,333.

To all whomz't may concern Be it known that I, IDA S. SHULTZ, a citizenof the United States, residing at Easton, in the county of Northamptonand State of Pennsylvania, have invented a new and useful Improvement inThermostatic Alarms, of which the following is a specification.

This invention relates to an alarm especially adapted for use inconnection with incubators, and the object of the invention is to givean alarm upon the rise or fall of temperature in the egg chamber beyondcert-ain predetermined limits.

It is usually considered inadvisable to allow the temperature to fallbelow 100 or to rise above 103 during the first week of incubation, thetemperature being usually held at either 102 or 103 during that period.During the latter part of the hatch, especially during the third week,the temperature is often allowed to run higher than 103 .although at notime is it desirable to have the temperature fall below 100 or 101,although slight changes in temperature are believed to be beneficial bymany experienced operators.

The object of this invention is to permit changes of temperature onlywithin the limits of safety and to signal the attendant as soon as thetemperature drops below or rises above the safety limit.

With this object in view, the invention consists in providing anelectrically operated alarm, which is preferably in the form of a bell,the usual damper rod lifted and lowered by the action of the thermostatforming a part of the electric circuit, and a pair of adjustable armsextending above and be low said rod and marking the safety limit of itsrise and fall, a circuit through the bell being completed and an alarmgiven as soon as the rod contacts with either of said arms.

In the accompanying drawings, Figure 1 is a side elevation, a portion ofan incubator and an incubator heater being shown, and my device beingapplied thereto, the electric circuit being indicated in diagram. Fig. 2is a plan view of Fig. 1, the circuit being shown diagrammatically. Fig.3 is a section on the line 33 of Fig. 1.

In these drawings, 1 represents an incubator of any make, 2 the heater,3 the damper rod, 4 the damper, and 5 the thermostat rod or needle. Therod 3 is pivotally mounted upon a suitable support 6. These parts arecommon to incubators in general use, and the details of theirconstruct-ion vary with different makes, although the general principleof all of them is substantially the same. It will of course beunderstood that as the temperature of the egg chamber falls, the damperrod 3 also falls and permits the damper 1 to close the upper end of theflue in the heater 2, thus throwing the heat into the egg chamber. Asthe heat increases and passes beyond a certain limit the rod 3 will riseand will lift the damper l, thus permitting heat to escape. Ordinarily aproperly adjusted thermostat with a properly hung damper will hold thetemperature at the point desired which is usually in the neighborhood of103 degrees F. However, there are certain limitations to the ability ofa thermostat to control the temperature, and it will be obvious that ifthe lamp should burn out from lack of oil, or if a thick crust ispermitted to form upon the top of the wick, or if the flame is turnedtoo low, the thermostat can accomplish nothing beyond closing the damperand retaining what heat there may be in the egg chamber but if theamount furnished is insuflicient no action of the thermostat canincrease it or prevent a further drop in temperature. Furthermore, ifthe lamp flame should creep up 01' be left too high, or if the machineis located in a building exposed to the sun, the temperature is likelyto rise faster than the lifting of the damper can reduce it. In order togive warning of these accidental or unexpected conditions, I place uponthe top of the incubator 1, a suitable base 7 upon which is mounted apost 8, at one end, and a bracket 9 at the opposite end, the bracketbeing provided with what may be termed upper and lower horizontallyprojecting arms 10. Suitable adjusting screws 11 work vertically throughthe bracket arms 10 and diverging arms 12 are pivotally connected to theposts 8. The arms 12 are not pivoted loosely but are locked sufficientlytight to the post, so that they will remain in an adjusted position. Topermit of exactness of adjustment, the screws 11 are provided, and bybringing them to bear upon the arms, the levers can be adjusted towardeach other with such exactness that the space between them willcorrespond exactly to the movement of the damper rod, vertically, duringa variation of three degrees in the temperature of the egg chamber. Itwill of course be understood that no two thermostats will expand orcontract exactly alike, and consequently the exact adjustment of thearms 12 can be determined only by experimenting in connection with thethermostat actually used, and this adjustment will also depend to someextent upon the distance of the said arms from the pivotal point of thedamper rod 3. It will be assumed however, that said arms are so adjustedthat when the temperature falls to 100 the damper will engage one of thearms, that adjusted by the lower screw 11, and when the temperaturereaches 103 or more preferably 103. or even 104, that it will engage theother arm. It is of course advisable to adjust said arms so that theywill not interfere with the proper movement of the damper rod withinnormal limits.

Attached to the damper rod 3 in any manner and at any desired point, asfor example at its pivotal point with the support 6 is one end of anelectric circuit 13, and the other end of said circuit is connected tothe post 8 at the point where the levers 12 are pivoted. This circuitincludes a battery 14 and a bell 15 may be placed upon the incubator, orthe bell may be located in another room or building and at any reasonable distance from the machine. It will be obvious that as soon as thedamper rod engages either one of the levers, a circuit will be completedthrough said levers, through the circuit wire 13, including the bell andbattery and through the damper rod. This will cause the bell to ring andwill give any person within hearing, warning of the fact that thetemperature has either fallen below or risen above the safety limit.

What I claim is The combination with an incubator having a damper rod,of a suitable base secured upon said incubator and at right angles tothe damper rod, a post carried by said base, a bracket having laterallyextending arms car ried by the base, the said post and bracket beingupon opposite sides of the damper rod, diverging arms carried by thepost, the damper rod working between said arms, adjusting screws workingthrough the arms of the bracket and adapted to engage respectively saidarms and an electric circuit including said arms and the damper rod, a

suitable alarm forming also a part of said circuit.

IDA S. SHULTZ. lVitnesses:

E. C. YEAGER, H. B. SHULTZ.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

